I. Field of the Invention
This disclosure relates generally to apparatus and methods for estimating a position. More particularly, the disclosure relates to extended assistance data used in taking measurements at a current geographical area (or first geographical area) and a future geographical area (or second geographical area).
II. Background
Today, a mobile device may determine a location estimate based on signals it receives from base stations and/or global positioning satellites. To assist a mobile device in determining which signals to seek, a network may provide the mobile device with an assistance data message containing assistance information. This assistance information may be localized to a particular area. The mobile device may use the provided assistance data when in that particular area. When the mobile device moves from a first geographical area to a new geographical area, the mobile device may request and receive new assistance data for the new geographical area. Each time the mobile device needs new assistance data because the previously received assistance data is inapplicable or unusable in a new geographical area, the mobile device exchanges messages with the network. This exchange of additional messages increases message traffic in a wireless communications system leaving less bandwidth for other traffic, delays initiation of finding a first fix when in a new geographical area, and leads to additional power consumption from transmitting and receiving additional messages between the mobile device and the network, each of which contribute to battery consumption on the mobile device. Therefore, a method and apparatus is desired to reduce message traffic, increase a time to first fix and decrease battery power consumption.